Rail Signaling & Wayside Equipment worked example

Rework Cost at 81% share of flags confirmed as real defects: a worked example in rail signaling & wayside equipment

What does the result look like when share of flags confirmed as real defects reaches 81%? The full calculation is worked below with real intermediate numbers. A production lead quantifies the rework hit after an inspection batch flags solder defects on a run of wayside interface modules.

The inputs for this scenario

  • Assemblies flagged for rework: 120 units (unchanged)
  • Rework labor & materials per assembly: 340 $/unit (unchanged)
  • Share of flags confirmed as real defects: 81 % (raised for this scenario; the documented default is 70)
  • Line setup & retest charge: 2,500 $ (unchanged)

Working through the calculation

  • Applying the documented formula (Rework cost = flagged assemblies x rework cost per unit x confirmation rate% + setup/retest) to the inputs above produces each figure below.
  • At this operating point the engine returns 35,548 $ for total rework cost, the number this scenario is built around.
  • At this operating point the engine returns 296 $ / piece for rework cost per unit.
  • At this operating point the engine returns 33,048 $ for variable rework cost.
  • At this operating point the engine returns 2,500 $ for fixed rework cost adder.

How this compares with the baseline

  • Against the tool's baseline example, where share of flags confirmed as real defects sits at 70% and the headline result is 31,060 $, this scenario comes in 14.45% above the baseline at 35,548 $.
  • A figure at this level is achievable when share of flags confirmed as real defects is genuinely sustained, not just peaked for a shift. It assumes one average per-unit rework cost and one confirmation rate for the batch; a mix of easy and hard defects, or escalating retest requirements, will skew the average.

Results at a glance

  • Total rework cost: 35,548 $ (headline result)
  • Rework cost per unit: 296 $ / piece
  • Variable rework cost: 33,048 $
  • Fixed rework cost adder: 2,500 $

Run it with your numbers

  • Every input above is editable in the live Rework Cost calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.